Arsene Wenger handed young defender Konstantinos Mavropanos his Arsenal debut as Henrikh Mkhitaryan came into a much-changed side at former club Manchester United.

David Ospina, Hector Bellerin and Granit Xhaka - the skipper at Old Trafford - were the only players to retain their starting role after Thursday's Europa League semi-final first-leg 1-1 draw with Atletico Madrid.